for Journals by Title or ISSN
for Articles by Keywords
help
  Subjects -> CHEMISTRY (Total: 762 journals)
    - ANALYTICAL CHEMISTRY (45 journals)
    - CHEMISTRY (527 journals)
    - CRYSTALLOGRAPHY (22 journals)
    - ELECTROCHEMISTRY (24 journals)
    - INORGANIC CHEMISTRY (40 journals)
    - ORGANIC CHEMISTRY (40 journals)
    - PHYSICAL CHEMISTRY (64 journals)

ANALYTICAL CHEMISTRY (45 journals)

Accounts of Chemical Research     Full-text available via subscription   (115 followers)
ACS Combinatorial Science     Full-text available via subscription   (7 followers)
Acta Analytica     Hybrid Journal   (6 followers)
Advances in Analytical Chemistry     Open Access   (15 followers)
American Journal of Analytical Chemistry     Open Access   (25 followers)
Analytica Chimica Acta     Hybrid Journal   (30 followers)
Analytical and Bioanalytical Chemistry     Hybrid Journal   (21 followers)
Analytical Chemistry     Full-text available via subscription   (213 followers)
Analytical Chemistry Insights     Open Access   (16 followers)
Analytical Letters     Hybrid Journal   (6 followers)
Analytical Spectroscopy Library     Full-text available via subscription   (10 followers)
Annual Review of Analytical Chemistry     Full-text available via subscription   (8 followers)
Chinese Journal of Analytical Chemistry     Full-text available via subscription   (2 followers)
Combinatorial Chemistry - an Online Journal     Open Access   (2 followers)
Comprehensive Analytical Chemistry     Full-text available via subscription   (4 followers)
Critical Reviews in Analytical Chemistry     Hybrid Journal   (22 followers)
Current Analytical Chemistry     Hybrid Journal   (5 followers)
Drug Testing and Analysis     Hybrid Journal   (3 followers)
Electroanalysis     Hybrid Journal   (3 followers)
Field Analytical Chemistry and Technology     Hybrid Journal   (4 followers)
Handbook of Analytical Separations     Full-text available via subscription   (1 follower)
Handbook of Thermal Analysis and Calorimetry     Full-text available via subscription  
International Journal of Analytical Chemistry     Open Access   (18 followers)
International Journal of Chemical and Analytical Science     Full-text available via subscription   (2 followers)
International Journal of Environmental Analytical Chemistry     Hybrid Journal   (4 followers)
International Journal of Polymer Analysis and Characterization     Hybrid Journal   (2 followers)
ISRN Analytical Chemistry     Open Access   (13 followers)
ISRN Chromatography     Open Access   (1 follower)
Journal of Analytical & Bioanalytical Techniques     Open Access   (4 followers)
Journal of Analytical Atomic Spectrometry     Full-text available via subscription   (6 followers)
Journal of Analytical Chemistry     Hybrid Journal   (11 followers)
Journal of Electroanalytical Chemistry     Hybrid Journal   (2 followers)
Journal of Essential Oil Research     Hybrid Journal   (2 followers)
Journal of Radioanalytical and Nuclear Chemistry     Hybrid Journal   (2 followers)
Journal of Thermal Analysis and Calorimetry     Hybrid Journal   (15 followers)
Main Group Metal Chemistry     Full-text available via subscription  
Microchemical Journal     Hybrid Journal   (2 followers)
Phytochemical Analysis     Hybrid Journal   (1 follower)
Polish Journal of Chemical Technology     Open Access   (2 followers)
Reviews in Analytical Chemistry     Full-text available via subscription   (5 followers)
Surface and Interface Analysis     Hybrid Journal   (12 followers)
Techniques and Instrumentation in Analytical Chemistry     Full-text available via subscription   (5 followers)
TrAC Trends in Analytical Chemistry     Full-text available via subscription   (15 followers)
Trends in Environmental Analytical Chemistry     Hybrid Journal  
Vibrational Spectroscopy     Hybrid Journal   (8 followers)
Journal of Analytical Chemistry    [13 followers]  Follow    
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
     ISSN (Print) 1608-3199 - ISSN (Online) 1061-9348
     Published by Springer-Verlag Homepage  [2187 journals]   [SJR: 0.322]   [H-I: 17]
  • Simultaneous separation of perfluorocarbons and oxyfluorocarbons using
           capillary gas chromatography: analysis of the products of
           hexafluoropropene oxidation
    • Abstract: Abstract Capillary gas chromatography was investigated as a method of analyzing and quantifying the products of the high-temperature gas-phase oxidation of hexafluoropropene. Standard polysiloxane polymer stationary phases were found to be ineffective in separating the aggressive mixture of oxyfluorocarbons and perfluorocarbons. Adsorbent type stationary phases provided better retention and separation for the exceedingly volatile components than polar/non-polar liquid phases. The tested silica-based porous-layer phase was found to be susceptible to degradation through interaction with acid fluoride species. The analysis was ultimately performed in two stages. Authentic oxidation product gas samples were first analyzed, then treated with aqueous potassium hydroxide to remove carbonyl compounds and resampled to determine oxygen content on the same system. Detector response factor ratios for a number of different perfluorocarbons were obtained, the information which is useful for chromatographic method development but is conspicuously absent in the open literature. The system was found to have good long-term stability with calibration deviations of less than 3% over a period of two years.
      PubDate: 2014-01-01
       
  • Determination of polar pesticides in soil by micellar electrokinetic
           chromatography using QuEChERS sample preparation
    • Abstract: Abstract The optimal conditions for the separation of pesticides of the following classes: phenoxy carboxylic acids, sim-triazines, triazinones, chloroacetamides, urea derivatives, neonicotinoids, carbamates, triazoles, imidazoles, benzimidazoles, and phosphorus organic compounds by micellar electrokinetic chromatography have been selected. A method for determining 27 polar pesticides in soil using QuEChERS sample preparation has been developed. The recovery of pesticides was from 31 to 104%. The lower limits of the found pesticide concentrations in soil taking into account preconcentration were 0.01–0.4 mg/kg. The relative standard deviation of the results of analysis does not exceed 10%.
      PubDate: 2014-01-01
       
  • Dynamic extraction in microcolumn as a method for the sample preparation
           of oil-contaminated soils
    • Abstract: Abstract A method is proposed for the sample preparation of oil-contaminated soils based on the dynamic extraction of petroleum products in a microcolumn of special design. By an example of the analysis of GSO (State Standard Sample) 8673-2005 of an oil-contaminated soil and model soil samples, a comparative evaluation of the efficiency of dynamic and batch (shaking in a shaker) extraction for the sample preparation of oil-polluted soils is carried out. The concentration of petroleum products in the extracts was determined by IR spectrometry. It was shown that the recovery of petroleum products into carbon tetrachloride in extraction in a microcolumn is, on the average, 50% higher than that in mixing the sample and reagent in a shaker. The rapid and efficient extraction of petroleum products in a microcolumn is possible because of dynamic extraction occurring at a constant renewal of the reagent.
      PubDate: 2014-01-01
       
  • Arsenic species analysis in freshwater using liquid chromatography
           combined to hydride generation atomic fluorescence spectrometry
    • Abstract: Abstract A novel pretreatment system and method for arsenic species continuous analysis of arsenite, arsenate, monomethylarsenate (MMA) and dimethylarsonate (DMA) in freshwater using liquid chromatography combined to hydride generation atomic fluorescence spectrometry (LC-HG-AFS) was designed. Arsenic species of As(III), As(V), MMA and DMA in freshwater samples can be well separated, and the analytical time using the developed method is shortened twice compared to the conventional analytical procedure. Besides, the signal of As(V) can be increased by about 50% and the sensitivity to As(V) has been enhanced. The common coexisting ions in freshwater samples have no interferences with arsenic speciation analysis. A sensitive, low cost and interference-free procedure was developed and successfully applied to arsenic speciation in freshwater with the recoveries of four arsenic species within 89.2–106.2%. LC-HG-AFS has good prospects for speciation analysis of trace and ultra trace elements allowing for hydride generation.
      PubDate: 2014-01-01
       
  • Influence of cobalt chloride concentration on the selectivity of a
           tetrathiocyanocobaltate-selective electrode to thiocyanate
    • Abstract: Abstracts The influence of the background concentration of CoCl2 on the selectivity of a Co(SCN) 4 2− -selective electrode based on QASs to thiocyanate is studied. The introduction of CoCl2 into a solution binds cobalt released from the membrane as thiocyanate complexes. A high selectivity of a Co(SCN) 4 2− -selective electrode to rhodanide ions is due to the formation of better extractable complexes between cobalt and SCN-compared to acido complexes of competitive ions. An introduction of 3.5 M CoCl2 into a solution enhances selectivity to SCN− by four orders of magnitude.
      PubDate: 2014-01-01
       
  • Reduction of matrix effects in ICP-MS by optimizing settings of ion optics
    • Abstract: Abstract The effect of ion optics settings on the degree of suppression of analyte signals due to the presence of different basic elements in a sample solution, such as manganese, copper, indium, lanthanum, hafnium, and lead, was investigated on an example of an XSeries II inductively coupled plasma mass spectrometer. The effect of atomic mass and the concentration of the matrix element on the optimum values of ion optics settings and the change in the analyte signals was studied. It was shown that a decrease in the potential of the extractor lens to −300 V can significantly reduce the matrix effect. As an example, the results of determining impurity elements in solutions containing up to 1 g/L of lanthanum were obtained using standard settings of the spectrometer with a reduced voltage on the extractor. It was shown that the optimization of ion optics settings enables the use of more concentrated solutions, thus reducing the detection limits for elements by several times.
      PubDate: 2014-01-01
       
  • Detection of salicylic acid by electrocatalytic oxidation at a
           nickel-modified glassy carbon electrode
    • Abstract: Abstract An electrochemical biosensor for the accurate determination of salicylic acid (SA) is prepared by potentiostatic deposition of nickel on the glassy carbon electrode (GCE). The electrochemical performance of the Ni/GCE film and the parameters affecting its activity are investigated by cyclic voltammetry, amperometry and electrochemical impedance spectroscopy (EIS). The electrooxidation of SA is significantly enhanced on Ni/GCE, compared to GCE. Indeed, the modified electrode has a fast response (less than 3 s) and excellent linear behavior over a wide SA concentration range (2 μM-0.55 mM) with a detection limit (LD) of 0.5 μM (signal/noise = 3) under the optimal conditions. Moreover, the stability and the reproducibility of the biosensor are satisfactorily evaluated.
      PubDate: 2014-01-01
       
  • Analytical determination of nimesulide and ofloxacin in pharmaceutical
           preparations using square-wave voltammetry
    • Abstract: Abstract The electrochemical behaviour and analytical detection procedure for nimesulide (NIM) and ofloxacin (OFX) and their assay in commercial formulations were evaluated using square-wave voltammetry (SWV) combined with a hanging mercury drop electrode (HMDE). All experimental and voltammetric conditions were previously optimized to obtain the best analytical signal in terms of intensities and profile of the reduction peaks. For NIM, the peak currents were related to the one-electron reduction of a nitro group to a stable radical anion, which is followed by a one-electron transfer and a protonation step with a consequent formation of a nitrosoanion. The voltammetric results indicated that the mechanism of OFX involved the transfer of two electrons and two protons in a totally irreversible reduction related to the conversion of a ketone group to an alcohol group. Analytical parameters such as linearity range, equations of the analytical curves, correlation coefficients, detection and quantification limits, recovery efficiency, and relative standard deviation for repeatability and reproducibility experiments were compared to similar results obtained by the use of UV-Vis spectrophotometry, and the results showed that the voltammetric procedure using HMDE is suitable to determine pharmaceutical compounds in complex samples. The applicability of the proposed procedure was tested on pharmaceutical formulations of NIM and OFX by observing the stability, specificity, recovery and precision of the procedure in tablets, oral solution and ophthalmic solution.
      PubDate: 2014-01-01
       
  • Determination of matrine in medicine and bio-fluids based on inhibition of
           luminol-myoglobin chemiluminescence
    • Abstract: Abstract A green, rapid and sensitive flow injection procedure based on the inhibition of the chemiluminescence (CL) intensity from the luminol-myoglobin (Mb) system is proposed for the determination of matrine. The decrement of CL signal was linear with the logarithm of the matrine concentration over the range from 10 to 1000 ng/mL (R 2 = 0.9978) offering a detection limit of 3.5 ng/mL. At a flow rate of 2.0 mL/min, one analysis cycle, including sampling and washing, could be accomplished in 0.5 min with a relative standard deviation (RSD) of less than 5.0%. The sensitive flow injection method was successfully applied to the determination of matrine in pharmaceutical injection and human serum, with recoveries from 94.1 to 113.4% and RSDs of less than 5.0%.
      PubDate: 2014-01-01
       
  • Determination of carbamazepine: a comparison of the differential pulse
           voltammetry (DPV) method and the immunoassay method in a clinical trial
    • Abstract: Abstract We conducted a clinical trial to analyze human serum containing carbamazepine by using the differential pulse voltammetry (DPV) method with a glassy carbon electrode, and compared it with the fluorescence polarization immunoassay (FPIA). Thirty patients, who visited our hospital to have their serum carbamazepine level checked, were enrolled. Ten mL of venous blood was collected from each patient and analyzed by DPV and FPIA methods. The correlation between the carbamazepine concentrations determined by DPV and FPIA was good, with an RSQ of 0.998. The similarity of the results indicates that these two methods can be used interchangeably. The DPV method using a glassy carbon electrode may be a potential alternative method to determine the carbamazepine level in human serum.
      PubDate: 2014-01-01
       
  • Determination of herbicides and their metabolites in natural waters by
           capillary zone electrophoresis combined with dispersive liquid-liquid
           microextraction and on-line preconcentration
    • Abstract: Abstract A method has been proposed for the determination of 17 herbicides and their metabolites in natural waters by capillary zone electrophoresis with UV detection at 190 nm. Dispersive liquid-liquid microextraction with trichloromethane has been used for pesticide recovery from water. The high sensitivity of determination has been provided by additional intracappilary preconcentration: the limits of pesticide detection in water involving off- and on-line preconcentration are 0.5–3.0 μg/L. The analysis takes 1–1.5 h; the relative standard deviation of the analysis results does not exceed 5%.
      PubDate: 2014-01-01
       
  • A membrane electrode reversible to zinc ions based on a polymer chelating
           adsorbent
    • Abstract: Abstract The sorption of a diazocompound on a highly basic anionite has been studied. The analytical properties of the modified adsorbent have been considered. A technology has been proposed for the production of a film membrane Zn-SE utilizing modified amberlite as the ionophore. The composition of the membrane has been optimized and the main potentiometric characteristics of zinc-selective electrode have been determined. The advantages of the proposed Zn-SE construction are explained.
      PubDate: 2014-01-01
       
  • Using gold nanoparticles in spectrophotometry
    • Abstract: Abstract Published data on the use of gold nanoparticles in spectrophotometry are summarized. Data on methods for preparing gold nanoparticles and their optical properties are presented. The main approaches on which spectrophotometic methods of substance determination using gold nanoparticles are based are discussed. Examples of determining of metal ions, anions, and organic compounds are presented.
      PubDate: 2014-01-01
       
  • Ion selective electrode for uranium based on composite multiwalled carbon
           nanotube-benzo-15-crown-5 in PVC matrix coated on graphite rod
    • Abstract: Abstract Development of a composite multiwalled carbon nanotube (MWNT) polyvinyl chloride (PVC) with benzo-15-crown-5 (B15C5) as ionophore sensor responsive to uranyl ion is described. The composite MWNT-PVC membrane containing the active ingredients was casted on the surface of a graphite rod. The sensor incorporates B15C5 as electroactive material, ortho-nitrophenyl octyl ether (o-NPOE) as a plasticizer and sodium tetraphenyl borate (NaTPB) as an ion discriminator. The sensor displays a rapid and linear response over the concentration range of 1 × 10−1 to 1 × 10−7 M with a slope of 29.9 ± 0.4 mV per decade. The detection limit of this electrode was found to be 5.4 × 10−8 M and the working pH range is from 2.5 to 4.5. Interference from many inorganic cations viz. Na+, K+, Sr2+, Zn2+ and Fe3+ is negligible for the sensor. Application to the determination of uranium in ores and effluent samples gives results with good correlation which are comparable with data obtained by inductively coupled plasma atomic emission spectrometry. The electrode has been characterized using surface techniques.
      PubDate: 2014-01-01
       
  • Using high resolution and dynamic reaction cell for the improvement of the
           sensitivity of direct silicon determination in uranium materials by
           inductively coupled plasma mass spectrometry
    • Abstract: Abstract The paper describes solving the problem of direct silicon determination at low levels in uranium materials, caused by the spectral interferences of polyatomic ions and the high value of blank levels, using inductively coupled plasma mass spectrometry (ICP MS). To overcome the interference problem, two primary techniques have been applied: double focusing high-resolution ICP MS and dynamic reaction cell (DRC) filled with highly reactive ammonia gas. All measurements were performed at high resolution (m/Δm = 4000) on an Element-2 mass spectrometer and pressurized mode of a dynamic reaction cell on an Elan DRC II mass spectrometer. The ways to reducing background levels are investigated. The effects of operating conditions, such as plasma parameters, DRC system original parameters, and uranium matrix influence on the analytical signals of silicon at m/z = 28 have been observed for different mass spectrometer types. The detection limits and the random error characteristics (relative standard deviation) of silicon determination in uranium materials were estimated.
      PubDate: 2013-12-01
       
  • Mass spectrometric analysis of the        class="a-plus-plus">13C/       class="a-plus-plus">12C abundance ratios in vine
           plants and wines depending on regional climate factors (Krasnodar krai and
           Rostov oblast, Russia)
    • Abstract: Abstract Distribution of 13C/12C isotopes in vegetative (roots, grapevine, leaves) and generative (berries) parts of vine plants of the West European genetically different varieties Cabernet Sauvignon and Aligoté growing on soils of Krasnodar krai and Rostov oblast, as well as autochthonous varieties Sibirkovy and Krasnostop Zolotovsky growing in Rostov oblast, has been studied using isotopic mass spectrometry methods. It has been shown that the variations of δ13C values in plant tissues and berries are related to the climatic conditions of plant growth: moisture (a sum of annual precipitation) and temperature (a sum of annual effective temperatures). The carbon isotope ratios of vegetative and generative parts of vine plants have been found to be noticeably affected by vine varieties. The different 13C contents in ethanol produced from wine of the Aligoté and Cabernet Sauvignon varieties grown in two Russian vineyard regions are due to vine growth conditions, variety attribution and wine production techniques. An analytically significant parameter determined as exemplified by the Aligoté and Cabernet Sauvignon varieties in fermentation of vine harvested in different seasons and in both vineyard regions was an increased 13C content in ethanol with respect to dry (non-volatile) residue in wine after distillation of ethanol. This characteristic has been determined by a systematic difference of about 1–2‰ between the δ13C value of ethanol and the dry residue. A relative constancy in the carbon isotope composition of ethanol and of the dry residue in the final product is the basis for determining the authenticity of grape wines by means of isotopic mass spectrometry irrespective of natural factors.
      PubDate: 2013-12-01
       
  • Investigation of diterpenoid isosteviol ammonium derivatives by
           matrix-assisted laser desorption/ionization mass spectrometry
    • Abstract: Abstract Matrix-assisted laser desorption/ionization (MALDI) mass spectra of diterpenoid isosteviol ammonium derivatives have been analyzed. The compounds were synthesized as antibacterial agents. It has been found that peaks of salt cations were detected in positive ion MALDI mass spectra of mono-quaternary derivatives. The fragmentation of bis-quaternary salts depended on the distance between the ammonium centers. Clusters containing dication and acidic matrix anion have been observed for compounds with two quaternized nitrogen atoms connected by a nonanomethylene or a longer spacer. Similar clusters did not form for compounds containing pentamethylene or a shorter spacer between two quaternized nitrogen atoms.
      PubDate: 2013-12-01
       
  • Transport of ions and charged droplets from the atmospheric region into a
           gas dynamic interface
    • Abstract: Abstract Transport of charged particles from the region of their generation to vacuum through a transport capillary with various length-to-diameter ratios L/D = 0.8, 32.5 and 420 is studied. It is shown the process is affected mostly by the geometrical features of the transport capillary and the structure of particles, ions, or droplets, due to the method of their generation (ESI and APCI). A method for distinguishing ions and droplets inside a gas dynamic interface is utilized and supported by computational simulation. The droplets are shown to dominate in the current by ESI for all the capillaries studied. It is shown experimentally that space charge effects predominated over diffusion ones for all practically important currents and capillaries. The estimations show that electrostatic repulsion and their attraction to capillary walls because of the mirror charge induced by all particles are close in effect.
      PubDate: 2013-12-01
       
  • Use of [13C]/[       class="a-plus-plus">12C] ratios as an indicator
           of the role of microorganisms in protection of plants from the phytotoxic
           action of naphthalene
    • Abstract: Abstract Using molecular and isotopic mass spectrometry, we investigated the toxic effect of naphthalene as a representative of polycyclic aromatic hydrocarbons (PAHs) on plants growing under sterile conditions and plants inoculated with microorganisms capable and incapable of naphthalene degradation. Tobacco plants of the Samsun variety were grown in a closed gas-nutrient system on a mineral medium with sucrose as a carbon source. Naphthalene used as a toxicant at a concentration of 5.2 × 10−4% contained 13C isotope whose amount was characterized by the value δ13C = +281.4 ± 0.6‰ relative to the PDB standard and differed from that of sucrose, the main source of carbon (δ13C = −12.0 ± 0.1‰). Degradation of naphthalene was determined by the inclusion of its carbon in metabolic CO2 and plant tissues (the root, stem, leaves). The effect of naphthalene on plants was indicated by the rates of O2 production and CO2 uptake during the light period as compared with the dark period of exposure. A decrease of the toxic effect of naphthalene on plants was observed only at the inoculation of plants with Pseudomonas aureofaciens BS1393 rhizosphere bacteria bearing plasmid pBS216, which controls the naphthalene biodegradation ability. The occurrence of other heterotrophic microorganisms incapable of naphthalene degradation had no similar protective effect.
      PubDate: 2013-12-01
       
  • Negative ion mass spectra of hydrophilic naphtoquinones
    • PubDate: 2013-12-01
       
 
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
Fax: +00 44 (0)131 4513327
 
About JournalTOCs
API
Help
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-2014